content: /* Copyright (C) 2016-2018 Alibaba Group Holding Limited
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  ==============================================================================*/
  
  // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf;
  
  import java.util.List;
  import java.util.Map;
  
  /**
   * Base interface for methods common to {@link Message} and
   * {@link Message.Builder} to provide type equivalency.
   *
   * @author jonp@google.com (Jon Perlow)
   */
  public interface MessageOrBuilder extends MessageLiteOrBuilder {
  
    // (From MessageLite, re-declared here only for return type covariance.)
    @Override
    Message getDefaultInstanceForType();
  
    /**
     * Returns a list of field paths (e.g. "foo.bar.baz") of required fields
     * which are not set in this message.  You should call
     * {@link MessageLiteOrBuilder#isInitialized()} first to check if there
     * are any missing fields, as that method is likely to be much faster
     * than this one even when the message is fully-initialized.
     */
    List<String> findInitializationErrors();
  
    /**
     * Returns a comma-delimited list of required fields which are not set
     * in this message object.  You should call
     * {@link MessageLiteOrBuilder#isInitialized()} first to check if there
     * are any missing fields, as that method is likely to be much faster
     * than this one even when the message is fully-initialized.
     */
    String getInitializationErrorString();
  
    /**
     * Get the message's type's descriptor.  This differs from the
     * {@code getDescriptor()} method of generated message classes in that
     * this method is an abstract method of the {@code Message} interface
     * whereas {@code getDescriptor()} is a static method of a specific class.
     * They return the same thing.
     */
    Descriptors.Descriptor getDescriptorForType();
  
    /**
     * Returns a collection of all the fields in this message which are set
     * and their corresponding values.  A singular ("required" or "optional")
     * field is set iff hasField() returns true for that field.  A "repeated"
     * field is set iff getRepeatedFieldCount() is greater than zero.  The
     * values are exactly what would be returned by calling
     * {@link #getField(Descriptors.FieldDescriptor)} for each field.  The map
     * is guaranteed to be a sorted map, so iterating over it will return fields
     * in order by field number.
     * <br>
     * If this is for a builder, the returned map may or may not reflect future
     * changes to the builder.  Either way, the returned map is itself
     * unmodifiable.
     */
    Map<Descriptors.FieldDescriptor, Object> getAllFields();
  
    /**
     * Returns true if the given oneof is set.
     * @throws IllegalArgumentException if
     *           {@code oneof.getContainingType() != getDescriptorForType()}.
     */
    boolean hasOneof(Descriptors.OneofDescriptor oneof);
  
    /**
     * Obtains the FieldDescriptor if the given oneof is set. Returns null
     * if no field is set.
     */
    Descriptors.FieldDescriptor getOneofFieldDescriptor(
        Descriptors.OneofDescriptor oneof);
  
    /**
     * Returns true if the given field is set.  This is exactly equivalent to
     * calling the generated "has" accessor method corresponding to the field.
     * @throws IllegalArgumentException The field is a repeated field, or
     *           {@code field.getContainingType() != getDescriptorForType()}.
     */
    boolean hasField(Descriptors.FieldDescriptor field);
  
    /**
     * Obtains the value of the given field, or the default value if it is
     * not set.  For primitive fields, the boxed primitive value is returned.
     * For enum fields, the EnumValueDescriptor for the value is returned. For
     * embedded message fields, the sub-message is returned.  For repeated
     * fields, a java.util.List is returned.
     */
    Object getField(Descriptors.FieldDescriptor field);
  
    /**
     * Gets the number of elements of a repeated field.  This is exactly
     * equivalent to calling the generated "Count" accessor method corresponding
     * to the field.
     * @throws IllegalArgumentException The field is not a repeated field, or
     *           {@code field.getContainingType() != getDescriptorForType()}.
     */
    int getRepeatedFieldCount(Descriptors.FieldDescriptor field);
  
    /**
     * Gets an element of a repeated field.  For primitive fields, the boxed
     * primitive value is returned.  For enum fields, the EnumValueDescriptor
     * for the value is returned. For embedded message fields, the sub-message
     * is returned.
     * @throws IllegalArgumentException The field is not a repeated field, or
     *           {@code field.getContainingType() != getDescriptorForType()}.
     */
    Object getRepeatedField(Descriptors.FieldDescriptor field, int index);
  
    /** Get the {@link UnknownFieldSet} for this message. */
    UnknownFieldSet getUnknownFields();
  }
  